Robert Irwin Celebrates 'Absolute Best Sister' and New Mom Bindi Irwin on National Siblings Day

Robert Irwin had nothing but love for big sister Bindi Irwin on National Siblings Day. To mark the occasion on Sunday, the 17-year-old took to social media to pay tribute to the "absolute best sister" and "amazing mom," sharing an adorable photo of himself, Bindi, and her newborn daughter Grace Warrior Irwin Powell, whom she welcomed last month with husband Chandler Powell.

Celebrating the occasion, Irwin excitedly wrote, "Happy [National Siblings Day]" alongside the photo, which showed the beaming new mom holding little Grace, Irwin posing beside them. He added that he has "the absolute best sister - Grace definitely has an amazing mum." The duo's mom, Terri Irwin, also commemorated the day on Twitter, where she celebrated the bond between her children by sharing four throwback photos.

Of course, Bindi also had beaming things to say about her brother, a newly-minted uncle, in her own tribute. Shared to Instagram, Bindi wrote, "I'm thankful every day that I get to be your sister. Thank you for being such a wonderful friend and light in my life." The sweet message was shared alongside one of the throwback images Terri shared showing the young siblings posing with a snake.

The adorable posts had many Crikey! It's the Irwins fans weighing in, with one person responding to Terri's post with, "Bindi and Robert are the sweetest sibling duo! They are a real testament to the amazing job you have done raising them Terri! Steve would be so proud of you all!" Another person added, "Heartwarming to see that many times apples don't fall from the tree!" Over on Irwin's post, one person wrote, "you guys are both so lucky to have each other!" with another adding, "I think in the future Grace and her funcle will be a dynamic duo."


National Siblings Day 2021 marked the first since Irwin became an uncle and Bindi became a mom. Bindi welcomed her daughter, her first child with her husband, on March 25, a date that also happened to be her and Powell's first wedding anniversary. Following Grace's birth, Irwin was quick to celebrate, excitedly writing on social media, "Let the uncle adventures begin! Love you so much, Grace."